I bought a $20 version of the SAME one on Amazon.com WITH free 2 day shipping.
Works perfect although the cable is not long you either need a computer to be close or have a laptop.
I can zoom in and out on trichomes to see what color they are.
Be warned though unless you have a steady hand it's kinda hard to get a nice zoom, most of the time you have to press up on the buds so you don't sway so much.
For $20 though I was like what the hell, I take pictures with it and it works fine for my needs.
Can't find the one I purchased but here is one very similar
http://www.amazon.com/AGPtek®-Digital-Microscope-Camera-20-200X/dp/B004Q86ONO/ref=sr_1_123?ie=UTF8&qid=1386531232&sr=8-123&keywords=Microscope
I'm betting they are all manufactured at the same location and just slap brands/labels on them for different companies.
Extra Edit: That one I posted is only 200x, I bought a 800x one for $20, can't find it with the first minute of searching so I gave up lol.